Beta-amino - beta,beta - bis(fluoroalkyl)carbonyl compounds and process for preparing the same



United States Patent 3,546,276 fi-AMINO 3,13 BIS(FLUOROALKYL)CARBONYL COMPOUNDS AND PROCESS FOR PREPARING THE SAME David M. Gale, Wilmington, Del., assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware No Drawing. Filed Oct. 22, 1965, Ser. No. 502,611 Int. Cl. C07c 101/00, 121/42 US. Cl. 260-482 4 Claims ABSTRACT OF THE DISCLOSURE Fluoroalkylideneimines can be reacted with compounds containing a methylene group activated by an adjacent carbonyl group in the presence of a Friedel-Crafts catalyst to give fi-amino-fl,fl-bis(fiuoroalkyDcarbonyl compounds. The ;8-amino-;8,/8-bis(fiuoroalkyl)carbonyl compounds are useful as degreasing agents for metals.

DESCRIPTION OF THE INVENTION wherein R and R each represent fluorine, chlorine, perfluoroalkyl, w-chloroperfiuoroalkyl or w-hydroperfluoroalkyl, in which each alkyl group contains 1-6 carbon atoms; R is CN or R is hydrocarbyl or O-hydrocarbyl, each hydrocarbyl group containing 1-8 carbon atoms and being free of aliphatic unsaturation; and R and R together represent the group --(CH where n is 3 or 4.

The term free of aliphatic unsaturation means that there are no aliphatic double or triple bonds in the hydrocarbyl groups, i.e., the only unsaturation which may be present in these groups is aromatic unsaturation. Thus the hydrocarbyl groups include alkyl, aryl, aralkyl and alkaryl.

In general, the compounds of the invention are colorless liquids which exhibit good solvent properties.

The novel compounds of this invention can be prepared by reacting a fluoroalkylideneimine of the formula with an active methylene compound of the formula R CH COR at a temperature bet-ween about 50200 C. in the presence of a Friedel-Crafts catalyst. R through R are defined as previously. The reaction is carried out by mixing the imine, active methylene compound and catalyst under essentially anhydrous conditions at 50 to 200 C., and preferably between about 75 and 150 C. No solvent is necessary and preferably none is employed. However, if desired, inert solvents such as the aliphatic and cycloaliphatic hydrocarbons, e.g., hexane, octane, cyclohexane, or other solvents such as tetrachloroethane, tetrachloroethylene, carbon disulfide, and the like, may be employed.

The two reactants can be used in any desired molar ratio, but are preferably employed in ratios of 0.52.0 moles of active methylene compound per mole of imine. The Friedel-Crafts catalyst may be present in a molar ratio, based on the amount of imine used, between 0.01:1 and 0.25:1, depending upon the sensitivity of the reactants and products to acid catalyzed decomposition and on the ability of the product to complex with the catalyst. Catalysts which may be employed include aluminum chloride, aluminum bromide, boron trifluoride, boron trichloride, antimony pentachloride, zinc chloride, ferric chloride, hydrogen fluoride, stannous chloride, and the like. Time and pressure are not critical in the process, although 4-18 hours and autogenous pressure are usually employed.

The fluoroalkylideneimines used herein as reactants are obtained by reacting a polyfiuoroketone with at least one molar equivalent of ammonia at 50 to 10 C. followed by dehydration of the resulting aminohydroxy polyfluoroalkane with a dehydrating agent in the presence of an acid acceptor, and then distilling to recover the imine. The imine reactant also may be prepared by reacting hydrazoic acid with a polyfiuorothioketone. Both these aforedescr'ibed methods are disclosed and claimed in the co-assigned patent application U.S. Ser. No. 250,501, filed Jan. 10, 1963. The first method for preparing the imine reactants is also described by Middleton et al. in J. Org. Chem. 30, 1398 (1965).

The examples which follow further illustrate the products and process of this invention. The reactor lining referred to in the examples as Hastelloy is a nickel-ironmoly bdenum alloy.

A mixture of 20 g. cyclohexanone, 1 g. of zinc chloride and 34 g. of hexafluoroisopropylideneimine was heated in a Hastelloy-lined autoclave for 8 hours at 125 C. The bomb was cooled and vented and the recovered product distilled through a spinning-band column. The resulting product, 24.4 g., was 2-(2-aminohexafluoroisopropyl)cyclohexanone, B.P. C. (6 mm.), n 11.4037.

Analysis.Calcd for C H F NO (percent): C, 41.08; H, 4.22; F, 43.30. Found (percent): C, 41.86; H, 4.50; F, 42.65.

The infrared spectrum showed peaks at 2.93, 3.0, 6.19 1. (NH 3.39, 3.48,:1. (saturated CH), 5.80 1. (C=O) and strong CF absorption.

The mass spectrum showed a parent peak at m/e 263 and the expected fragmentation.

2-(2-aminohexafiuoroisopropyl)cyclopentanone can be obtained by the same procedure, substituting cyclopentanone for cyclohexanone. This compound is characterized by: B.P. 6061 C. (55 mm.); 11 1.3880; and showed the elemental analysis:

Analysis.Calcd for C H NOF (percent): C, 38.56; H, 3.50; N, 5.62; F, 45.57. Found (percent): C, 38.83; H, 3.74; N, 5.54; F, 45.57.

F NMR showed a pair of quartets at +230 and +530 c.p.s. from FCCI CCI F (J =9 c.p.s.).

3 EXAMPLE 11 A mixture of 10 g. of methyl cyanoacetate, 2.6 g. of zinc chloride and 17 g. of hexafluoroisopropylideneimine was heated in a Hastelloy-lined autoclave at 100 for 8 hours. After cooling and venting the bomb the reaction mixture was combined with 3 g. of solid sodium bicarbonate and washed well with ether. Distillation of the ether washings aflorded 7.6 g. of 2-carbomethoxy-3- amino-3-trifluoromethyl-4;4,4-trifluorobutyronitrile, B.P. 5759 C. (0.75 mm.) The infrared spectrum showed bands at 2.92, 2.97 and 6.13,u for NH -absorption, a band at 4.41 1 for CEN and at 5.67; for C=O. The mass spectrum showed a major peak at the parent-NH and was consistent with the assigned structure. The P NMR showed an A B multiplet (1:9) centered at +4222 c.p.s. (external FCC1 at 56.4 me.) and the H NMR showed NH at 'T 7.3, (EH 0 at 6.11 and 4 Analysis.Ca1cd for C H N F O (percent): C, 31.82; H, 2.67; N, 10.61. Found (percent): C, 32.83; H, 2.52; N, 10.71.

at 1- 6.03; the P NMR showed a singlet at +4208 c.p.s. from external F CCl at 5 6.4 mc.

Analysis.Calcd for C H NO F (percent): C, 32.33; H, 3.06; N, 4.72; F. 38.35. Found (percent): C, 33.13; H, 3.30; N, 5.34; F, 38.22.

The following table provides additional specific examples of products of this invention which can be prepared at 5.70. 25 by the described procedure.

TABLE Imine (catalyst) Active methylene compound Product H H CFzCl COzOHzOH; (CFgl) 13)=NH 011301120 C 0112C C0115 H2N-'O-CH 0 F201 0 0 CUHE (I? 0 F20 FZH ON (CF2HCF2)2C=NH NCCHzCCHz(CH2)aCH HzN-C CH 211012) CFzCFzH COG/3H" CH3 CH3 ll 1? i (01cm) OFaC=NH Q-o c 01120 0 CHr-Q-CH: c 0 (ZnClz) I (\JF Cl CH HzNC-CE CH,

l(3O CHz CH3 0 omen 3 (a (GF2)5CF3 /COOCH C=NH CHBO C-CHzCCH; HzNC-C1\I CF3(CF2)0 (CFzMCFa COOH;

0 0 a 1 II II I (G3F(1Z)2CCT%\IH l -N H i" i? u [C1O(g:l( ();F2)@]2C=NH CHaCHzOCCHzCOCHzCHz (CF2)0CF2C1 /COO2H5 a H2NC 0s (OF2)0CF2C1 l(l]OCzH5 HO F20 u u C=NH CBH5CH2OCCHZCOCH2CBH5 (llFzcFzH /COCH2C5H5 HCF2(CF2)3 HzNC CH (A1013) (CF3)2CF2H [(EOCHZCGHE e t CF 3 C=NH l C-NH1 C2175 CzFs The products of the invention are useful as metal degreasing agents. They can be employed in the vapor phase either at atmopsheric or reduced pressure, or in the liquid phase at elevated temperatures. For example, strips were cut from a steel coupon containing an oily film to protect it from rusting. One strip was held in the vapors of the amine from hexafluoroisopropylideneimine and cyclohexanone for about a minute. Another strip was likewise treated with the amine from hexafiuoroisopropylideneimine and dimethylmalonate. These strips, together with an untreated strip were placed in a beaker containing a few drops of water. The amine-treated strips rusted rapidly (in about 30 min.) while the untreated strip did not.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Compounds represented by the formula:

wherein hydrocarbyl in each instance is defined as of 1 to 8 carbon atoms free of aliphatic unsaturation and wherein R' and R are each fluorine, chlorine, perfluoroalkyl, w-chloroperfluoroalkyl or w-hydroperfluoroalkyl, in which each alkyl is of 1-6 carbon atoms.

2. Compounds represented by the formula:

C FzR' C O O Hydrocarbyl H2N-C CH 0 F211 0 O 0 Hydrocarbyl 4. Process for preparing compounds of the formula (IJFZR C O 0 Hydrocarbyl rnN-o 0H 0 FzR C O O Hydrocarbyl wherein with from 0.5 to 2.0 moles per mole of said imine compound of a compound of the formula C O O Hydrocarbyl C 0 O Hydrocarbyl wherein R R and hydrocarbyl are as defined above in the presence of from 0.01 to 0.25 moles of a Friedel- Crafts catalyst per mole of said imine compound.

References Cited Middleton, J. Org. Chem, 30, p. 1402 (1965).

JOSEPH P. BRUST, Primary Examiner US. Cl. X.R. 

